Tension device for band-saws.



M. T. WERTENBAKBR.

TENSION DEVIGEFOR BAND SAWS.

APPLICATION FILED MAY 13, 1911.

1,069,748. Patented Aug. 12,1913.

3 SHEETSSEBET 1.

Y d g ventor WZW/Q W Attorneys M. T. WERTENBAKER. TENSION DEVICE FORBAND SAWS.

APPLICATION FILED MAY 13, 1911.

Patented Aug. 12, 1913.

3 SHEETS-SHEET 2.

7 22 Z ZZ Witnesses Attorneys M. T. WERTENBAKER.

TENSION DEVICE FOR BAND SAWS.

APPLICATION FILED MAY 13, 1911.

1,069,748. r I Patented Aug. 12, 1913.

3 SHEETSSHET 3.

nventor Witnesses f Attorneys UNTTED STATES PATENT QFFTQE.

MILTON T. WERTENBAKER, OF PARKERSBURG, WEST VIRGINIA.

TENSION DEVICE FOR BAND-SAWS.

To all whom it may concern:

Be it known that I, MILTON T. XVERTEN- BAKER, a citizen of the UnitedStates, residing at Parkersburg, in the county of Vood and State ofWVest Virginia, have invented a new and useful Tension Device for Band-Saws, of which the following is a specification.

This invent-ion relates to an improved mechanism for placing undertension the cutting edges of a double out band saw.

The primary object of the invention is to provide means for tighteningthe cutting edge of the saw to increase its cutting efficiency.

In the drawings :-Figure l is a front elevation of the saw support. Fig.2 is a top plan view. Fig. 3 is a side view. Figs. 4, 5 and 6 are detailviews of the mechanism for imparting movement to the shaft bearings.Fig. 7 is a detail View of the eccentric shaft which raises the bearing,the cam surface being shown smooth. Fig. 8 is a front elevation showinga slightly modified form of mechanism for shifting the bearings. Fig. 9is a top plan view of said modified form.

In the drawings 10 designates the bed plate which is provided with thespaced bearing supports 11 and 12. These supports receive-the standards13 which are either formed integral with or rigidly support a yoke 14.This yoke 14 embraces the lower portion of the sectional bearing 15which supports the hollow shaft 16 on which the wheel 17 is mounted. Thebearing 15 is provided with the transverse bore 18 which registers withapertures 19' formed in the arms 15 of the yoke. Arranged to extendthrough said bearing and through the arms 15 of said yoke is a cam shaft20 which is held against longitudinal movement by means of the jam nut-s20. Secured adjacent to the ends of said shaft 20 and held againstdisplacement by the nuts 21 are a plurality of levers 22, which whenactuated rotate the shaft 20: These levers extend above the bearings 15and are connected by a rod 23 which is secured at its center to aplunger 24 said plunger being mounted for reciprocatory movement between guides 25 and 26 which are supported by a bracket 27, said bracketbeing secured to the bearing 15. Arranged on the outer end of theplunger 24 is an arm 28 which Specification of Letters Patent.

Application filed May 13, 1911.

Patented Aug. 12,1913.

Serial No. 627,038.

terminates at a point in alinement with the bore of the shaft 16.Arranged to reciprocate within said shaft is a rod 29 which is securedto the arm 28, thus a reciproca tory movement imparted to the arm 28will swing the levers 22 to rotate the shaft 20, the swinging of saidlevers 22 causing the reciprocation of the plunger 24 which will in turnimpart movement to the rod 29. This rod 29 extends entirely through thesleeve 16 and is connected on the other side of the support to a secondarm 28 which is in turn connected to a piston 24, the structure forrotating the shaft 20 and the construction and arrangement of said shaftbeing duplicated on this side of the support. Thus it will be noted thatas the rod 29 is moved to the left as shown in Fig. l, the shaft whichextends through the hearing arranged on the left hand side of thesupport will turn to the left, the cam surface of said rod contact-ingwith the bearing to raise the same thus tilting the sleeve on which thewheel 17 is mounted. It will be noted that as the levers 22 are swung torotate the shaft 20 which raises the bearing on the left hand side ofthe support a corresponding rotation will be imparted to the shaft 20arranged on the other side of the support, the cams being so arrangedthat when one of the bearings is raised the other bearing will belowered.

As before stated the primary object of the invention is to increase thetension of the cutting edges of the saw this being accomplished byshifting the supporting wheel by means of the bearings 15, it beingnoted that when one bearing is raised and the other is lowered one edgeof the wheel will be raised and that when the raising mechanism isshifted by moving the bracket 28 or in any other manner, the otherhearing will be raised and the other edge of the supporting wheel.raised. In this manner a double edge band saw may have either of itscutting edges placed under tension, thus increasing the efficiency ofthe saw. In order to add to the tension created by the tilting of thesupporting wheel in cases where but one adjustable wheel and onestationary wheel is used, the bearings are given a slight lateralmovement, this movement being secured by threading the bore whichreceives the shaft 20 to receive a screw threaded cam 20 (Figs. 4 and 5)of said shaft. Thus as said shaft is rotated by means of the levers 22-the bearings will not only be raised by the action of the cam, but saidbearing in addition to being lifted by this cam action will receive amovement which is occasioned by the screw threading of the bore andshaft 20, this movement causing a slight twist of the bearing. As beforestated the rotary movement imparted to the shaft 20 on one side of thesupport is transmitted to the similar shaft which pierces the bearingarranged on the other side. One of these shafts is provided with a righthand thread and the other with a left hand thread. Thus it will be seenthat the rotary movement of the shaft willoscillate the bearings, thesaw thus being mounted upon a support which is arranged to oscillate,the mounting being such that either of the edges of the supporting wheelmay be raised, means being provided for consonantly raising one edge andlowering the other.

The supporting wheel is initially leveled by means of the verticallyadjustable rods 35 which contact with the standards 13 which are raisedand lowered by means of turn buckles 36 the ends of said rods beingsupported by the weighted yoke 37, this yoke being forced downward tobring the wheel 17 in contact with the saw..

In the modified form shown in Figs. 8 and 9 the guides for the plunger24 are supported by a bracket 38 which is secured to an upright, theplunger 24 being con nected to the rod 29 by means of an arm 39. In thisform of the invention the shaft 20 is connected by means of a knuckle oruni versal joint 40, to the portion 42 of the bracket 38. It will thusbe noted that the threaded portion 2O of the shaft 20 in conjunctionwith the means for rotating the same will produce the necessary actionor oscillatory movement in the supporting wheel so that either edge ofthe saw will be placed under a tension and lead the saw in the properdirection.

The skewing of the bearings leads the saw into the material. Attentionis called to the fact that the simultaneous lowering of one bearing andraising of the other places one edge of the saw under tension, which isdesirable in view of the fact that the What is claimed is I p 1. In amechanism of the class described, a saw supporting wheel, a shaftsupporting said wheel, a plurality of independently movable bearingssupporting said shaft, said bearings being disposed on opposite sides ofsaid wheel, and means for simultaneously raising one of said bearings,lowering the other and skewing the same to lead the saw into thematerial.

2. In a mechanism of the character described, a saw supporting wheel, ashaft supporting said wheel, a plurality of independently movablebearings, disposed on 0pposite sides of said wheel and supporting saidshaft and threaded cams for simultaneously raising one of said bearings,lowering the other, and skewing the same in opposite directions.

3. In a mechanism of the class described, a saw supporting wheel, ashaft supporting said wheel, bearings supporting said shaft, a yokesupporting each of said bearings and means supported by said yoke andeX- tending within said bearings for imparting a lateral and a verticalmovement to the same, said bearings moving in opposite directions.

4. In a mechanism of the character described, a saw supporting wheel,- ahollow shaft supporting said wheel, a plurality of independently movablebearings supporting said shaft, a rod mounted to reciprocate within saidshaft, cam means for imparting vertical movement to each of saidbearings, said rods transmitting the movement of one cam to the other.

5.- In a mechanism of the character described, a saw supporting wheel, ahollow shaft supporting said wheel, a plurality of independently movablebearings supporting said shaft, a rod mounted to reciprocate within saidshaft, a supporting bracket arranged adjacent to each of said bearings,a plurality of guides supported by said bracket, a plunger mounted formovement between said guides, an arm connecting said plunger with saidrod, a cam shaft passing transversely through each of said bearingsandan operative connection between said shaft and said plunger.

In testimony that I claim the foregoingas my own, I have hereto affixedmy signature in the presence of two witnesses.

MILTON T. WERTENBAKER.

Witnesses:

F. B. OoH'sEnRnITnR, LENA VVILLsoN.

Copies of this patent may be obtained. for five cents each, byaddressing the Commissioner of iatents, Washington, I). C.

